Efecto de un yogur con inulina sobre la función intestinal de sujetos sanos o constipados / Effect of an inulin containing yougurt on intestinal function of healthy and constipated volunteers

The effect of the consumption of a yogurt with 2.36 g inulin and 1.77g polydextrose was evaluated in 33 healthy and 37 constipated adults, compared with the same product without inulin. The study includes two 5-week periods, one with the experimental product and the other with the control product, separated by a three week wash-out. The subjects had to ingest 1 yougurt/day during the first week of each period, 2/day during the third week and 3/day during the fifth week; simultaneously they had to register daily the intensity of the digestive symptoms as well as the frequency and consistency of their stools. The results showed that in healthy subjects, the intake of 2 yogurts with inulin or more per day significantly increased the digestive symptoms (p=0.03), due to a greater emission of rectal gas (p=0.000). Similar findings were observed in the constipated subjects consuming 3 yogurts daily (p=0.0085 y p=0.0048, respectively); stool frequency and consistency were significantly improved in these subjects (p=0.0039 and p=0.014, respectively). These results suggest that the consumption of 2 yogurts with inulin by day help to fight constipation in subjects with this complain while the intake of this same amount may increase discomfort in healthy subjects.

En 33 adultos sanos y 37 constipados se evaluó el efecto del consumo de un yogur que contenía 2.36 g de inulina y 1.77 g de polidextrosa, en comparación con un yogur control sin inulina. El estudio incluyó dos períodos de 5 semanas separados por tres semanas de reposo: uno con el producto experimental y otro con el control. Los sujetos consumieron 1 yogur al día la primera semana de cada período, 2 al día en la tercera y 3 al día en la quinta, y anotaron diariamente la intensidad de los síntomas digestivos así como el número de deposiciones emitidas y su consistencia. Los resultados muestran que a partir de un consumo diario de 2 yogures con inulina existe un aumento significativo de la sintomatología digestiva en los sujetos sanos (p=0.03), debido principalmente a la mayor emisión de gases rectales (p=0.000). Observaciones similares se realizaron en los sujetos constipados con el consumo de 3 productos diarios (p=0.0085 y p=0.0048, respectivamente); sin embargo en aquellos se observó además un mejoramiento significativo tanto en la frecuencia de las deposiciones (p= 0.0039) como en su consistencia (p= 0.014). Este estudio sugiere que el consumo del producto con inulina contribuye a aliviar las molestias de los individuos constipados pero que en los sujetos sanos un consumo de dos yogur al día aumenta los síntomas desagradables.

Efecto de la administración oral de inulina sobre el perfil de lípidos y la sensibilidad a la insulina en individuos con obesidad y dislipidemia / Effect of oral inulin administration on lipid profile and insulin sensitivity in subjects with obesity and dyslipidemia

BACKGROUND: Inulin is a non absorbable polysaccharide with prebiotic effects, whose influence on blood lipids or insulin sensitivity is not well known: AIM: To assess the effect of oral administration of inulin on lipid profile and insulin sensitivity in dyslipidemic obese subjects. MATERIAL AND METHODS: A clinical trial, double blind, randomized with placebo was carried out in 12 obese, hypertrygliceridemic and hypercholesterolemic subjects between 19 and 32 years old. The subjects were randomized to receive 7 g/day of inulin or placebo in the morning, during 4 weeks. Biochemical and metabolic profiles and euglycemic-hyperinsulinemic clamp technique for assessing insulin sensitivity, before and after pharmacological intervention were performed. RESULTS: After inulin administration, there was a significant reduction of total cholesterol (248.7 +/- 30.5 and 194.3 +/- 39.8 mg/dL; p = 0.028), low density lipoprotein (LDL), cholesterol (136.0 +/- 27.8 and 113.0 +/- 36.2 mg/dL; p = 0.028), very low density lipoproteins (VLDL) (45.9 +/- 18.5 and 31.6 +/- 7.2 mg/dL; p = 0.046) and trygliceride concentrations (235.5 +/- 85.9 and 171.1 +/- 37.9 mg/dL; p = 0.046). No effect of inulin on insulin sensitivity was observed. CONCLUSIONS: The oral inulin administration reduced total cholesterol, LDL cholesterol, VLDL and trygliceride levels in dyslipidemic and obese subjects, without modifications in the insulin sensitivity.

Applications of inulin and oligofructose in health and nutrition.

Inulin and oligofructose belong to a class of carbohydrates known as fructans. The main sources of inulin and oligofructose that are used in the food industry are chicory and Jerusalem artichoke. Inulin and oligofructose are considered as functional food ingredients since they affect the physiological and biochemical processes in rats and human beings, resulting in better health and reduction in the risk of many diseases. Experimental studies have shown their use as bifidogenic agents, stimulating the immune system of the body, decreasing the pathogenic bacteria in the intestine, relieving constipation, decreasing the risk of osteoporosis by increasing mineral absorption, especially of calcium, reducing the risk of atherosclerosis by lowering the synthesis of triglycerides and fatty acids in the liver and decreasing their level in serum. These fructans modulate the hormonal level of insulin and glucagon, thereby regulating carbohydrate and lipid metabolism by lowering the blood glucose levels; they are also effective in lowering the blood urea and uric acid levels, thereby maintaining the nitrogen balance. Inulin and oligofructose also reduce the incidence of colon cancer. The biochemical basis of these beneficial effects of inulin and oligofructose have been discussed. Oligofructose are non cariogenic as they are not used by Streptococcus mutans to form acids and insoluble glucans that are the main culprits in dental caries. Because of the large number of health promoting functions of inulin and oligofructose, these have wide applications in various types of foods like confectionery, fruit preparations, milk desserts, yogurt and fresh cheese, baked goods, chocolate, ice cream and sauces. Inulin can also be used for the preparation of fructose syrups.

Measurement of glomerular filtration rate using inulin prepared from Vernonia herbacea, a Brazilian native species

Vernonia herbacea (Vell.) Rusby (Asteraceae) is a perennial herb native to the cerrado vegetation of tropical areas in Brazil, which accumulates inulin in the underground reserve organs. The aim of this paper was to determine whether the inulin extracted from V. herbacea could replace commercial inulin for the measurement of glomerular filtration rate (GFR). Underground organs of vegetative plants were collected from a preserved area of the Brazilian cerrado. The inulin fraction utilized was obtained by ethanol precipitation after discarding the high molecular mass fructans in the freeze-thawing precipitate. GFR was determined in male Wistar rats anesthetized with inactin (100 mg/kg), which received intravenously commercial inulin obtained from Dahlia sp (Sigma) or Vernonia herbacea inulin (30 mg/100 g) as a priming dose and 0.05 mg min(-1) 100 g(-1) as a sustaining dose in isotonic saline at the rate of 0.055 ml/min. Clearance was determined during 3 periods, with urine collected from the bladder and blood from the carotid artery. There was no significant difference in the GFR measured by clearance of inulin from both sources even when the plasma concentration of inulin from V. herbacea was doubled. The mean arterial pressure did not vary after the application of both inulins, indicating that they do not produce systemic side effects. The filtered load and the excreted amount of inulin from V. herbacea were equal, showing that the substance is not influenced by tubular function. These results demonstrate that the inulin from V. herbacea can substitute for imported inulin for the determination of GFR and in experiments of kidney microperfusion as a marker of tubular water reabsorption.

Atividade da inulinase em leveduras e fermentaçöes de extratos de Helianthus tuberosus L / Inulinase activity in yeasts and fermentations of Helranthus tuberosus L extracts

Devido às concentraçöes de inulina em H. tuberosus, leveduras com boa produçäo de inulinase e alto potencial fermentativo säo imprescindíveis na viabilizaçäo industrial deste vegetal. Selecionando-se leveduras com estas propriedades, dentre 21 espécies avaliadas, encontram-se 11 linhagens com boa capacidade fermentativa. As leveduras com maior rendimento de produçäo de álcool foram Kluyveromyces marxianus, K. fragilis, Candida pseudotropicalis e Torulopsis coelliculosa. Em fermentaçöes sucessivas conduzidas a 30-C, com 15,6% de ART e por 48 horas, chegou-se a obter o rendimento médio de 85% em relaçäo ao teórico. Nestas condiçöes, após 10 horas de fermentaçäo encontraram-se rendimentos de 74,4% e uma taxa de fermentaçäo de 5,9g/1/h**-1. A atividade máxima da inulinase foi de 3,6micronM (equivalente frutose)/ml/min e verificou-se ocorrer repressäo catabólica da inulinase por frutose em K. marxianus e K. fragilis. Com estes resultados conclui-se ser viável a fermentaçäo de extratos sem prévia hidrólise, o que facilitará o processamento industrial de extratos de H. tuberosus